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FMDS Overview

FMDS, or Financial Market Data Server, is used to collect and store historical price data. FMDS serves historical data to the X_STUDY® charting application. X_STUDY then continues plotting real-time data obtained through the TT API™.

FMDS is comprised of two services: TT FMDS Feed and TT FMDS Responder. The TT FMDS Feed subscribes to gateways and records prices to historical data files. The TT FMDS Responder listens and fulfills requests for historical data from X_STUDY.

FMDS supports subscription of up to 2000 instruments. Once you subscribe to a contract or spread, FMDS is always recording. To ease the impact of historical data requests on your network, X_STUDY chunks requests into small messages and only asks for the number of bars to fill the screen.

Example: You may receive a hundred one-minute bars in the chart, but thousands more may be stored in FMDS.


  • The connection between X_STUDY and FMDS is non-persistent, only connecting as requests for new instruments or new rollup times are made.
  • FMDS is able to authenticate either directly to the gateway or with TT User Setup. Depending on the authentication method used, additional configuration may be needed. Refer to FMDS Authentication for details.